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Commit | Line | Data |
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d8a5ba45 MS |
1 | /* |
2 | FUSE: Filesystem in Userspace | |
d7133114 | 3 | Copyright (C) 2001-2006 Miklos Szeredi <miklos@szeredi.hu> |
d8a5ba45 MS |
4 | |
5 | This program can be distributed under the terms of the GNU GPL. | |
6 | See the file COPYING. | |
7 | */ | |
8 | ||
9 | #include <linux/fuse.h> | |
10 | #include <linux/fs.h> | |
51eb01e7 | 11 | #include <linux/mount.h> |
d8a5ba45 MS |
12 | #include <linux/wait.h> |
13 | #include <linux/list.h> | |
14 | #include <linux/spinlock.h> | |
15 | #include <linux/mm.h> | |
16 | #include <linux/backing-dev.h> | |
bafa9654 | 17 | #include <linux/mutex.h> |
d8a5ba45 | 18 | |
334f485d MS |
19 | /** Max number of pages that can be used in a single read request */ |
20 | #define FUSE_MAX_PAGES_PER_REQ 32 | |
21 | ||
08a53cdc | 22 | /** Maximum number of outstanding background requests */ |
f92b99b9 MS |
23 | #define FUSE_MAX_BACKGROUND 12 |
24 | ||
25 | /** Congestion starts at 75% of maximum */ | |
26 | #define FUSE_CONGESTION_THRESHOLD (FUSE_MAX_BACKGROUND * 75 / 100) | |
08a53cdc | 27 | |
1d3d752b MS |
28 | /** It could be as large as PATH_MAX, but would that have any uses? */ |
29 | #define FUSE_NAME_MAX 1024 | |
30 | ||
bafa9654 MS |
31 | /** Number of dentries for each connection in the control filesystem */ |
32 | #define FUSE_CTL_NUM_DENTRIES 3 | |
33 | ||
1e9a4ed9 MS |
34 | /** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem |
35 | module will check permissions based on the file mode. Otherwise no | |
36 | permission checking is done in the kernel */ | |
37 | #define FUSE_DEFAULT_PERMISSIONS (1 << 0) | |
38 | ||
39 | /** If the FUSE_ALLOW_OTHER flag is given, then not only the user | |
40 | doing the mount will be allowed to access the filesystem */ | |
41 | #define FUSE_ALLOW_OTHER (1 << 1) | |
42 | ||
bafa9654 MS |
43 | /** List of active connections */ |
44 | extern struct list_head fuse_conn_list; | |
45 | ||
46 | /** Global mutex protecting fuse_conn_list and the control filesystem */ | |
47 | extern struct mutex fuse_mutex; | |
413ef8cb | 48 | |
d8a5ba45 MS |
49 | /** FUSE inode */ |
50 | struct fuse_inode { | |
51 | /** Inode data */ | |
52 | struct inode inode; | |
53 | ||
54 | /** Unique ID, which identifies the inode between userspace | |
55 | * and kernel */ | |
56 | u64 nodeid; | |
57 | ||
9e6268db MS |
58 | /** Number of lookups on this inode */ |
59 | u64 nlookup; | |
60 | ||
e5e5558e MS |
61 | /** The request used for sending the FORGET message */ |
62 | struct fuse_req *forget_req; | |
63 | ||
d8a5ba45 | 64 | /** Time in jiffies until the file attributes are valid */ |
0a0898cf | 65 | u64 i_time; |
ebc14c4d MS |
66 | |
67 | /** The sticky bit in inode->i_mode may have been removed, so | |
68 | preserve the original mode */ | |
69 | mode_t orig_i_mode; | |
d8a5ba45 MS |
70 | }; |
71 | ||
b6aeaded MS |
72 | /** FUSE specific file data */ |
73 | struct fuse_file { | |
74 | /** Request reserved for flush and release */ | |
33649c91 | 75 | struct fuse_req *reserved_req; |
b6aeaded MS |
76 | |
77 | /** File handle used by userspace */ | |
78 | u64 fh; | |
c756e0a4 MS |
79 | |
80 | /** Refcount */ | |
81 | atomic_t count; | |
b6aeaded MS |
82 | }; |
83 | ||
334f485d MS |
84 | /** One input argument of a request */ |
85 | struct fuse_in_arg { | |
86 | unsigned size; | |
87 | const void *value; | |
88 | }; | |
89 | ||
90 | /** The request input */ | |
91 | struct fuse_in { | |
92 | /** The request header */ | |
93 | struct fuse_in_header h; | |
94 | ||
95 | /** True if the data for the last argument is in req->pages */ | |
96 | unsigned argpages:1; | |
97 | ||
98 | /** Number of arguments */ | |
99 | unsigned numargs; | |
100 | ||
101 | /** Array of arguments */ | |
102 | struct fuse_in_arg args[3]; | |
103 | }; | |
104 | ||
105 | /** One output argument of a request */ | |
106 | struct fuse_arg { | |
107 | unsigned size; | |
108 | void *value; | |
109 | }; | |
110 | ||
111 | /** The request output */ | |
112 | struct fuse_out { | |
113 | /** Header returned from userspace */ | |
114 | struct fuse_out_header h; | |
115 | ||
095da6cb MS |
116 | /* |
117 | * The following bitfields are not changed during the request | |
118 | * processing | |
119 | */ | |
120 | ||
334f485d MS |
121 | /** Last argument is variable length (can be shorter than |
122 | arg->size) */ | |
123 | unsigned argvar:1; | |
124 | ||
125 | /** Last argument is a list of pages to copy data to */ | |
126 | unsigned argpages:1; | |
127 | ||
128 | /** Zero partially or not copied pages */ | |
129 | unsigned page_zeroing:1; | |
130 | ||
131 | /** Number or arguments */ | |
132 | unsigned numargs; | |
133 | ||
134 | /** Array of arguments */ | |
135 | struct fuse_arg args[3]; | |
136 | }; | |
137 | ||
83cfd493 MS |
138 | /** The request state */ |
139 | enum fuse_req_state { | |
140 | FUSE_REQ_INIT = 0, | |
141 | FUSE_REQ_PENDING, | |
142 | FUSE_REQ_READING, | |
143 | FUSE_REQ_SENT, | |
a4d27e75 | 144 | FUSE_REQ_WRITING, |
83cfd493 MS |
145 | FUSE_REQ_FINISHED |
146 | }; | |
147 | ||
64c6d8ed MS |
148 | struct fuse_conn; |
149 | ||
334f485d MS |
150 | /** |
151 | * A request to the client | |
152 | */ | |
153 | struct fuse_req { | |
ce1d5a49 MS |
154 | /** This can be on either pending processing or io lists in |
155 | fuse_conn */ | |
334f485d MS |
156 | struct list_head list; |
157 | ||
a4d27e75 MS |
158 | /** Entry on the interrupts list */ |
159 | struct list_head intr_entry; | |
160 | ||
334f485d MS |
161 | /** refcount */ |
162 | atomic_t count; | |
163 | ||
a4d27e75 MS |
164 | /** Unique ID for the interrupt request */ |
165 | u64 intr_unique; | |
166 | ||
095da6cb MS |
167 | /* |
168 | * The following bitfields are either set once before the | |
169 | * request is queued or setting/clearing them is protected by | |
d7133114 | 170 | * fuse_conn->lock |
095da6cb MS |
171 | */ |
172 | ||
334f485d MS |
173 | /** True if the request has reply */ |
174 | unsigned isreply:1; | |
175 | ||
51eb01e7 MS |
176 | /** Force sending of the request even if interrupted */ |
177 | unsigned force:1; | |
178 | ||
f9a2842e MS |
179 | /** The request was aborted */ |
180 | unsigned aborted:1; | |
334f485d MS |
181 | |
182 | /** Request is sent in the background */ | |
183 | unsigned background:1; | |
184 | ||
a4d27e75 MS |
185 | /** The request has been interrupted */ |
186 | unsigned interrupted:1; | |
187 | ||
334f485d MS |
188 | /** Data is being copied to/from the request */ |
189 | unsigned locked:1; | |
190 | ||
9bc5ddda MS |
191 | /** Request is counted as "waiting" */ |
192 | unsigned waiting:1; | |
193 | ||
83cfd493 MS |
194 | /** State of the request */ |
195 | enum fuse_req_state state; | |
334f485d MS |
196 | |
197 | /** The request input */ | |
198 | struct fuse_in in; | |
199 | ||
200 | /** The request output */ | |
201 | struct fuse_out out; | |
202 | ||
203 | /** Used to wake up the task waiting for completion of request*/ | |
204 | wait_queue_head_t waitq; | |
205 | ||
206 | /** Data for asynchronous requests */ | |
207 | union { | |
e5e5558e | 208 | struct fuse_forget_in forget_in; |
b6aeaded | 209 | struct fuse_release_in release_in; |
3ec870d5 MS |
210 | struct fuse_init_in init_in; |
211 | struct fuse_init_out init_out; | |
361b1eb5 | 212 | struct fuse_read_in read_in; |
71421259 | 213 | struct fuse_lk_in lk_in; |
334f485d MS |
214 | } misc; |
215 | ||
216 | /** page vector */ | |
217 | struct page *pages[FUSE_MAX_PAGES_PER_REQ]; | |
218 | ||
219 | /** number of pages in vector */ | |
220 | unsigned num_pages; | |
221 | ||
222 | /** offset of data on first page */ | |
223 | unsigned page_offset; | |
224 | ||
334f485d | 225 | /** File used in the request (or NULL) */ |
c756e0a4 | 226 | struct fuse_file *ff; |
64c6d8ed | 227 | |
51eb01e7 MS |
228 | /** vfsmount used in release */ |
229 | struct vfsmount *vfsmount; | |
230 | ||
231 | /** dentry used in release */ | |
232 | struct dentry *dentry; | |
233 | ||
64c6d8ed MS |
234 | /** Request completion callback */ |
235 | void (*end)(struct fuse_conn *, struct fuse_req *); | |
33649c91 MS |
236 | |
237 | /** Request is stolen from fuse_file->reserved_req */ | |
238 | struct file *stolen_file; | |
334f485d MS |
239 | }; |
240 | ||
d8a5ba45 MS |
241 | /** |
242 | * A Fuse connection. | |
243 | * | |
244 | * This structure is created, when the filesystem is mounted, and is | |
245 | * destroyed, when the client device is closed and the filesystem is | |
246 | * unmounted. | |
247 | */ | |
248 | struct fuse_conn { | |
d7133114 MS |
249 | /** Lock protecting accessess to members of this structure */ |
250 | spinlock_t lock; | |
251 | ||
d2a85164 MS |
252 | /** Mutex protecting against directory alias creation */ |
253 | struct mutex inst_mutex; | |
254 | ||
bafa9654 MS |
255 | /** Refcount */ |
256 | atomic_t count; | |
257 | ||
d8a5ba45 MS |
258 | /** The user id for this mount */ |
259 | uid_t user_id; | |
260 | ||
87729a55 MS |
261 | /** The group id for this mount */ |
262 | gid_t group_id; | |
263 | ||
1e9a4ed9 MS |
264 | /** The fuse mount flags for this mount */ |
265 | unsigned flags; | |
266 | ||
db50b96c MS |
267 | /** Maximum read size */ |
268 | unsigned max_read; | |
269 | ||
413ef8cb MS |
270 | /** Maximum write size */ |
271 | unsigned max_write; | |
272 | ||
334f485d MS |
273 | /** Readers of the connection are waiting on this */ |
274 | wait_queue_head_t waitq; | |
275 | ||
276 | /** The list of pending requests */ | |
277 | struct list_head pending; | |
278 | ||
279 | /** The list of requests being processed */ | |
280 | struct list_head processing; | |
281 | ||
d77a1d5b MS |
282 | /** The list of requests under I/O */ |
283 | struct list_head io; | |
284 | ||
08a53cdc MS |
285 | /** Number of requests currently in the background */ |
286 | unsigned num_background; | |
287 | ||
a4d27e75 MS |
288 | /** Pending interrupts */ |
289 | struct list_head interrupts; | |
290 | ||
08a53cdc MS |
291 | /** Flag indicating if connection is blocked. This will be |
292 | the case before the INIT reply is received, and if there | |
293 | are too many outstading backgrounds requests */ | |
294 | int blocked; | |
295 | ||
296 | /** waitq for blocked connection */ | |
297 | wait_queue_head_t blocked_waitq; | |
de5e3dec MS |
298 | |
299 | /** waitq for reserved requests */ | |
300 | wait_queue_head_t reserved_req_waitq; | |
08a53cdc | 301 | |
334f485d MS |
302 | /** The next unique request id */ |
303 | u64 reqctr; | |
304 | ||
69a53bf2 MS |
305 | /** Connection established, cleared on umount, connection |
306 | abort and device release */ | |
095da6cb | 307 | unsigned connected; |
1e9a4ed9 | 308 | |
095da6cb MS |
309 | /** Connection failed (version mismatch). Cannot race with |
310 | setting other bitfields since it is only set once in INIT | |
311 | reply, before any other request, and never cleared */ | |
334f485d MS |
312 | unsigned conn_error : 1; |
313 | ||
0ec7ca41 MS |
314 | /** Connection successful. Only set in INIT */ |
315 | unsigned conn_init : 1; | |
316 | ||
9cd68455 MS |
317 | /** Do readpages asynchronously? Only set in INIT */ |
318 | unsigned async_read : 1; | |
319 | ||
095da6cb MS |
320 | /* |
321 | * The following bitfields are only for optimization purposes | |
322 | * and hence races in setting them will not cause malfunction | |
323 | */ | |
324 | ||
b6aeaded MS |
325 | /** Is fsync not implemented by fs? */ |
326 | unsigned no_fsync : 1; | |
327 | ||
82547981 MS |
328 | /** Is fsyncdir not implemented by fs? */ |
329 | unsigned no_fsyncdir : 1; | |
330 | ||
b6aeaded MS |
331 | /** Is flush not implemented by fs? */ |
332 | unsigned no_flush : 1; | |
333 | ||
92a8780e MS |
334 | /** Is setxattr not implemented by fs? */ |
335 | unsigned no_setxattr : 1; | |
336 | ||
337 | /** Is getxattr not implemented by fs? */ | |
338 | unsigned no_getxattr : 1; | |
339 | ||
340 | /** Is listxattr not implemented by fs? */ | |
341 | unsigned no_listxattr : 1; | |
342 | ||
343 | /** Is removexattr not implemented by fs? */ | |
344 | unsigned no_removexattr : 1; | |
345 | ||
71421259 MS |
346 | /** Are file locking primitives not implemented by fs? */ |
347 | unsigned no_lock : 1; | |
348 | ||
31d40d74 MS |
349 | /** Is access not implemented by fs? */ |
350 | unsigned no_access : 1; | |
351 | ||
fd72faac MS |
352 | /** Is create not implemented by fs? */ |
353 | unsigned no_create : 1; | |
354 | ||
a4d27e75 MS |
355 | /** Is interrupt not implemented by fs? */ |
356 | unsigned no_interrupt : 1; | |
357 | ||
b2d2272f MS |
358 | /** Is bmap not implemented by fs? */ |
359 | unsigned no_bmap : 1; | |
360 | ||
0cd5b885 MS |
361 | /** The number of requests waiting for completion */ |
362 | atomic_t num_waiting; | |
363 | ||
45714d65 MS |
364 | /** Negotiated minor version */ |
365 | unsigned minor; | |
366 | ||
d8a5ba45 MS |
367 | /** Backing dev info */ |
368 | struct backing_dev_info bdi; | |
f543f253 | 369 | |
bafa9654 MS |
370 | /** Entry on the fuse_conn_list */ |
371 | struct list_head entry; | |
372 | ||
373 | /** Unique ID */ | |
374 | u64 id; | |
375 | ||
376 | /** Dentries in the control filesystem */ | |
377 | struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES]; | |
378 | ||
379 | /** number of dentries used in the above array */ | |
380 | int ctl_ndents; | |
385a17bf JD |
381 | |
382 | /** O_ASYNC requests */ | |
383 | struct fasync_struct *fasync; | |
9c8ef561 MS |
384 | |
385 | /** Key for lock owner ID scrambling */ | |
386 | u32 scramble_key[4]; | |
0ec7ca41 MS |
387 | |
388 | /** Reserved request for the DESTROY message */ | |
389 | struct fuse_req *destroy_req; | |
d8a5ba45 MS |
390 | }; |
391 | ||
d8a5ba45 MS |
392 | static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb) |
393 | { | |
6383bdaa | 394 | return sb->s_fs_info; |
d8a5ba45 MS |
395 | } |
396 | ||
397 | static inline struct fuse_conn *get_fuse_conn(struct inode *inode) | |
398 | { | |
399 | return get_fuse_conn_super(inode->i_sb); | |
400 | } | |
401 | ||
402 | static inline struct fuse_inode *get_fuse_inode(struct inode *inode) | |
403 | { | |
404 | return container_of(inode, struct fuse_inode, inode); | |
405 | } | |
406 | ||
407 | static inline u64 get_node_id(struct inode *inode) | |
408 | { | |
409 | return get_fuse_inode(inode)->nodeid; | |
410 | } | |
411 | ||
334f485d | 412 | /** Device operations */ |
4b6f5d20 | 413 | extern const struct file_operations fuse_dev_operations; |
334f485d | 414 | |
e5e5558e MS |
415 | /** |
416 | * Get a filled in inode | |
417 | */ | |
418 | struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid, | |
9e6268db | 419 | int generation, struct fuse_attr *attr); |
e5e5558e MS |
420 | |
421 | /** | |
422 | * Send FORGET command | |
423 | */ | |
424 | void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req, | |
9e6268db | 425 | unsigned long nodeid, u64 nlookup); |
e5e5558e | 426 | |
04730fef | 427 | /** |
361b1eb5 | 428 | * Initialize READ or READDIR request |
04730fef | 429 | */ |
c756e0a4 | 430 | void fuse_read_fill(struct fuse_req *req, struct fuse_file *ff, |
361b1eb5 | 431 | struct inode *inode, loff_t pos, size_t count, int opcode); |
04730fef MS |
432 | |
433 | /** | |
434 | * Send OPEN or OPENDIR request | |
435 | */ | |
436 | int fuse_open_common(struct inode *inode, struct file *file, int isdir); | |
437 | ||
fd72faac MS |
438 | struct fuse_file *fuse_file_alloc(void); |
439 | void fuse_file_free(struct fuse_file *ff); | |
440 | void fuse_finish_open(struct inode *inode, struct file *file, | |
441 | struct fuse_file *ff, struct fuse_open_out *outarg); | |
442 | ||
c756e0a4 MS |
443 | /** Fill in ff->reserved_req with a RELEASE request */ |
444 | void fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags, int opcode); | |
445 | ||
04730fef MS |
446 | /** |
447 | * Send RELEASE or RELEASEDIR request | |
448 | */ | |
449 | int fuse_release_common(struct inode *inode, struct file *file, int isdir); | |
450 | ||
82547981 MS |
451 | /** |
452 | * Send FSYNC or FSYNCDIR request | |
453 | */ | |
454 | int fuse_fsync_common(struct file *file, struct dentry *de, int datasync, | |
455 | int isdir); | |
456 | ||
b6aeaded | 457 | /** |
1779381d | 458 | * Initialize file operations on a regular file |
b6aeaded MS |
459 | */ |
460 | void fuse_init_file_inode(struct inode *inode); | |
461 | ||
e5e5558e | 462 | /** |
1779381d | 463 | * Initialize inode operations on regular files and special files |
e5e5558e MS |
464 | */ |
465 | void fuse_init_common(struct inode *inode); | |
466 | ||
467 | /** | |
1779381d | 468 | * Initialize inode and file operations on a directory |
e5e5558e MS |
469 | */ |
470 | void fuse_init_dir(struct inode *inode); | |
471 | ||
472 | /** | |
1779381d | 473 | * Initialize inode operations on a symlink |
e5e5558e MS |
474 | */ |
475 | void fuse_init_symlink(struct inode *inode); | |
476 | ||
477 | /** | |
478 | * Change attributes of an inode | |
479 | */ | |
480 | void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr); | |
481 | ||
334f485d MS |
482 | /** |
483 | * Initialize the client device | |
484 | */ | |
485 | int fuse_dev_init(void); | |
486 | ||
487 | /** | |
488 | * Cleanup the client device | |
489 | */ | |
490 | void fuse_dev_cleanup(void); | |
491 | ||
bafa9654 MS |
492 | int fuse_ctl_init(void); |
493 | void fuse_ctl_cleanup(void); | |
494 | ||
334f485d MS |
495 | /** |
496 | * Allocate a request | |
497 | */ | |
498 | struct fuse_req *fuse_request_alloc(void); | |
499 | ||
500 | /** | |
501 | * Free a request | |
502 | */ | |
503 | void fuse_request_free(struct fuse_req *req); | |
504 | ||
334f485d | 505 | /** |
33649c91 | 506 | * Get a request, may fail with -ENOMEM |
334f485d | 507 | */ |
ce1d5a49 | 508 | struct fuse_req *fuse_get_req(struct fuse_conn *fc); |
334f485d | 509 | |
33649c91 MS |
510 | /** |
511 | * Gets a requests for a file operation, always succeeds | |
512 | */ | |
513 | struct fuse_req *fuse_get_req_nofail(struct fuse_conn *fc, struct file *file); | |
514 | ||
334f485d | 515 | /** |
ce1d5a49 MS |
516 | * Decrement reference count of a request. If count goes to zero free |
517 | * the request. | |
334f485d MS |
518 | */ |
519 | void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req); | |
520 | ||
521 | /** | |
7c352bdf | 522 | * Send a request (synchronous) |
334f485d MS |
523 | */ |
524 | void request_send(struct fuse_conn *fc, struct fuse_req *req); | |
525 | ||
334f485d MS |
526 | /** |
527 | * Send a request with no reply | |
528 | */ | |
529 | void request_send_noreply(struct fuse_conn *fc, struct fuse_req *req); | |
530 | ||
531 | /** | |
532 | * Send a request in the background | |
533 | */ | |
534 | void request_send_background(struct fuse_conn *fc, struct fuse_req *req); | |
535 | ||
5a5fb1ea | 536 | /* Abort all requests */ |
69a53bf2 MS |
537 | void fuse_abort_conn(struct fuse_conn *fc); |
538 | ||
e5e5558e MS |
539 | /** |
540 | * Invalidate inode attributes | |
541 | */ | |
542 | void fuse_invalidate_attr(struct inode *inode); | |
bafa9654 MS |
543 | |
544 | /** | |
545 | * Acquire reference to fuse_conn | |
546 | */ | |
547 | struct fuse_conn *fuse_conn_get(struct fuse_conn *fc); | |
548 | ||
549 | /** | |
550 | * Release reference to fuse_conn | |
551 | */ | |
552 | void fuse_conn_put(struct fuse_conn *fc); | |
553 | ||
554 | /** | |
555 | * Add connection to control filesystem | |
556 | */ | |
557 | int fuse_ctl_add_conn(struct fuse_conn *fc); | |
558 | ||
559 | /** | |
560 | * Remove connection from control filesystem | |
561 | */ | |
562 | void fuse_ctl_remove_conn(struct fuse_conn *fc); | |
a5bfffac TS |
563 | |
564 | /** | |
565 | * Is file type valid? | |
566 | */ | |
567 | int fuse_valid_type(int m); |